The problem I was having with v5.1.6.1 can be traced to a monitoring package we were trying out. It's a problem that manifests itself on heavily loaded servers with a ton of scheduled sessions. Working with the vendor to do further problem determination.
Now, as for v5.1.6.2, I've put it on my test servers and will go live with it this week. I need the fix for the EOT problem. Gretchen Thiele Princeton University